When precision is of paramount importance, experience makes a difference. An electronics laboratory initially contacted one of our competitors for the production of the toroidal power supply transformer highlighted here.
After analyzing the specifications, this company referred the client to us. With our strong background for pushing the boundaries of magnetics technology, we were able to engineer and manufacture a solution that fully aligned with the client’s needs.
Intended for use in a precision DC laboratory power supply, this transformer had multiple outputs of varying voltages and powers, all rectified and filtered, and extremely low common mode current specifications.
To offer some perspective, medical equipment typically requires leakage or common mode currents to be less than 50uA-a very demanding requirement. This particular application required 5uA-10 times more restrictive. Accomplishing this level of common mode or leakage current in a toroidal construction of this size was extremely challenging.
By design, toroidal cores provide a virtually perfect magnetic circuit, but makes common mode current reduction very difficult. We did a significant amount of research and analysis to determine the root cause of the stray currents and engineer a solution.
In addition to a winding configuration that reduced common mode rejection to a remarkably low level, our specification also met the challenging requirements due to the DC rectification and filtering, physical size, and thermal constraints.
Once we completed the design specs, our manufacturing engineers developed and implemented a proprietary new manufacturing process to accurately and repeatedly produce the transformer. With dimensions of 153mm OD x 78mm in height, elements of construction include a tape wound core, magnet wire, and UL Class F 155C Mylar insulation.
We executed a complex set of test and inspection processes to measure the turns ratio, resistance, common mode current, dielectric strength, and phasing. This device meets UL 61010-1 & IEC 61010-1 standards for laboratory equipment, test and measurement equipment, and industrial process controls.
Our 70+ years of engineering excellence in sensitive electronics, combined with our state of art manufacturing facility, allowed us to achieve an impressive 100% yield rate. We continue to manufacture this precision toroidal power supply transformer at the rate of 2500 units per year with a 16 week turnaround. To learn more about this project or our design and manufacturing capabilities, contact us today.
- Project Name & Description
Toroidal Power Transformer
Intended for a Precision DC Laboratory Power Supply, this transformer had multiple outputs of varying voltages and powers, all rectified and filtered, and extremely low common mode current specifications.
- Capabilities Applied/Processes
Common mode rejection and DC rectification design capabilities.
- Equipment Used to Manufacture Part
Toroidal transformer winder, tape wound core manufacturing equipment
- Overall Part Dimensions
153mm OD, 78mm Height
- Greatest Challenge
While Medical equipment requires leakage or common mode currents to be less than 50uA and is an exacting requirement, this transformer was 10 times more restrictive! Accomplishing this level of common mode or leakage current in a toroidal construction of this size was extremely challenging and required research to determine the true cause of the current and development of new manufacturing processes to ensure consistent, repeatable success.
- Material Used
Magnet wire, tape wound core, Mylar insulation
- Industry for Use
- In Process Testing/Inspection Performed
Turns ratio, Resistance, Common Mode current, dielectric strength, Phasing
- Delivery/Turnaround Time
- Delivery Location
- Standards Met
UL 61010-1 & IEC 61010-1: Laboratory equipment, Test & Measurement Equipment and Industrial Process Controls. UL Class F 155C Insulation system